1. Field of the Invention
The present invention relates to semiconductor fabricating equipment. More particularly, the present invention relates to semiconductor fabricating equipment that can minimize the influence of a process deteriorating material, that is generated during a first process, on a second process, whereby the first and second processes are performed step by step. This can significantly reduce the frequency of failures in patterning.
2. Description of the Related Art
In recent years, rapid developments have been made in the industrial fields of computers, information and communication, and aerospace. As a result, semiconductor products used in these various industries have become smaller, but generally perform higher functions.
The recent development trend toward lighter products with higher function in such a variety of industries has primarily resulted from an improvement in the functions of semiconductor products that can process a large quantity of data within a small unit of time, as well as a dramatic increase in the amount of data that can be stored in a given memory area. As a result, there is a continued need to accelerate the development of semiconductor products having these improved functions.
In general, the aforementioned semiconductor products have circuit wires that are precisely manufactured to have thicknesses as small as 0.1 xcexcm or so. As a result, very fine semiconductor fabricating equipment and related methods are required to manufacture such precise semiconductor products.
Such a semiconductor fabricating method generally consists of two steps: a first (or preceding) semiconductor fabricating step, and a second (or following) semiconductor fabricating step. The combination of these two general steps is required to make a circuit pattern having wires with thicknesses as small as 0.1 xcexcm or so.
Specifically, the first semiconductor fabricating step may include, for example, a photolithography process. In such a photolithography process, a thin photo-resistant layer that may remain or may be removed is formed by exposing light rays onto a pure silicon substrate, or wafer. A reticle, having an open part formed in relation to a circuit pattern, is placed over the photo-resistant layer to which the light rays will be exposed, and then the uncovered part of the wafer is exposed to the light rays to form a circuit pattern.
The second semiconductor fabricating step may include, for example, an ionimplantation process to implant ions into the open part; a deposition process to deposit a thin layer having different characteristics; an etching process to repeatedly form etching grooves or contact holes with an etchant or an etching gas; a metal process to electrically connect a circuit pattern; and the like.
The first and second semiconductor fabricating steps as such are generally performed in turn. At the same time, additional processes are performed to complete the fabrication of a semiconductor product. These additional processes may include making a semiconductor chip, a core part of any semiconductor product; packaging the product to make an electric connection with external devices and to protect the semiconductor chip from negative environmental factors; and testing the final semiconductor product.
When a semiconductor product is to be fabricated through a plurality of complex processes, it is preferable that a reduction in the thickness of wire be made by an improvement in the precision of the semiconductor fabricating equipment used to perform the first semiconductor fabricating step, rather than in the second semiconductor fabricating step.
In particular, in-line type photolithography equipment has been developed that sequentially includes a plurality of operational units such as a photo-resistant painting unit for pasting photo-resist to a wafer, a bake unit, an adhesion unit for improving adhesion between the wafer and the photo-resist, a stepper or a ray exposing unit, an interface unit and a developing unit, all of which are connected xe2x80x9cin-line.xe2x80x9d
When using such in-line photolithography equipment, wafers are in sequential motion and the first semiconductor fabricating step is in process continuously on successive wafers, so as to maximize efficiency of equipment. However, hexamethyldisilane (HMDS), a chemical used at an operational unit, i.e., at the adhesion unit, generates ammonia (NH4), which can result in a process failure at an adjacent process unit, e.g., at the bake unit. The problem of generating ammonia will be described in more detail below.
FIG. 1 illustrates changes in the quantity of ammonia generated from a sheet of wafers from the start to the completion of the operational processes. As shown in the graph in FIG. 1, there is a sudden change in the quantity of ammonia at some intervals, resulting in problems such as the occurrence of a T-top phenomenon, in which the top portion of the photo-resist layer remains as T-shaped, instead of forming a vertical profile after completion of wafer development at the developing unit.
The present invention is therefore directed to equipment for fabricating semiconductor products, and a method thereof, which substantially overcome one or more of the problems due to the limitations and disadvantages of the related art.
To solve the above and other problems, it is an object of the present invention to provide semiconductor fabricating equipment and a related method, that minimizes the negative influence of a material generated at one operational unit on an adjacent process unit during the course of a sequential in-line type processing.
In order to accomplish the above-noted and other objects of the present invention, a semiconductor fabricating equipment is provided comprising a first semiconductor process unit installed in a production line for performing first semiconductor fabricating processes that generate a process deteriorating gas; and a second semiconductor process unit installed in the production line for performing second semiconductor fabricating processes dependent on the first semiconductor processes, the second semiconductor processes being susceptible to operational failures if exposed to the process deteriorating gas. In this device, the second semiconductor process unit is installed at a higher level than the first semiconductor process unit, and clean air flows downward over the first and second semiconductor process units to carry the process deteriorating gas away from the second semiconductor process unit. The process deteriorating gas may be ammonia (NH4), for example.
The first semiconductor process unit may comprise an adhesion unit having an adhesion chamber that supplies an adhesion enhancing material for reinforcing adhesion between a wafer and a photo-resist layer, when the photo-resist layer is deposited onto the wafer. The second semiconductor process unit may comprise a bake unit that bakes the wafer that has the photo-resist layer formed on it.
Alternatively, a semiconductor fabricating device may be provided that comprises a first semiconductor process unit installed in a production line for performing first semiconductor fabricating processes that generate a process deteriorating gas; and a second semiconductor process unit installed in the production line for performing second semiconductor fabricating processes dependent on the first semiconductor processes, the second semiconductor processes being susceptible to operational failures if exposed to the process deteriorating gas. In this device, the first semiconductor process unit is installed in a first position and the second semiconductor process unit is installed at second position, and clean air flows from the first position to the second position to carry the process deteriorating gas away from the second semiconductor process unit. The process deteriorating gas may be ammonia (NH4), for example.
The first semiconductor process unit may comprise an adhesion unit having an adhesion chamber that supplies an adhesion enhancing material for reinforcing adhesion between a wafer and a photo-resist layer, when the photo-resist layer is deposited onto the wafer. The second semiconductor process unit may comprise a bake unit that bakes the wafer that has the photo-resist layer formed on it.
The above and other problems also may be overcome by a method of fabricating a semiconductor device including performing first semiconductor fabricating processes at a first location, the first semiconductor fabricating processes generating a process deteriorating gas; performing second semiconductor fabricating processes that are dependent upon the first semiconductor fabricating processes at a second location, the second semiconductor fabricating processes being susceptible to operational failures upon exposure to the process deteriorating gas; and flowing clean air from the second location to the first location to carry the process deteriorating gas away from the second location. In a preferred embodiment, the second location is higher than the first location.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.